Introduction: Turner's syndrome (TS) is associated with several manifestations the most frequent being short stature and hypogonadism. Some authors (Nadeem, 2012; Bakalov, 2008) reported that individuals with TS have increased risk of fractures, but the etiology and mechanism of bone fragility have not been yet fully elucidated and may be exacerbated by hormonal factors (Cintron, 2017; Soucek, 2015). Bone densitometry (BD) through the emission of double energy X radiation (DXA) is used to evaluate bone mineral content, but it analyzes only a two-dimensional measure of the bone and not its real volume. It is the most widely used method in the world to predict the risk of fractures (9). The interpretation of the BD in children should be performed by means of Z-score and, for individuals with short stature, it is recommended to adjust the values for bone age or for height/age (Brandao, 2009; Zerbini, 2006).
Objectives: To describe bone density at the lumbar spine (LS aBD) in a group of prepubertal TS individuals and compare the result after height/age correction.
Method: Retrospective analysis of medical records of healthy TS girls who had never received rhGH, anabolic steroids or estrogens. The variables analyzed were: karyotype, age at BD, weight, stature, body mass index (BMI) and BD (DEXA) result. We performed the adjusting of the BD result using the height/age (HA). Statistical analyses of the data were performed using SPSS software. The Wilcoxon test was used to compare the BD and BD-HA results; the Mann-Whitney test was used to compare the distribution of BDs in relation to karyotype and BMI; for the calculation of the probabilities was used the bootstrap technique, Monte Carlo method. The significance level of 5% (α=0.05) was used. The study was approved by the institutional Ethics Committee.
Results: 37 prepubertal girls were identified, 13 were selected after exclusion criteria. They were aged between 10-13 years-old. Regarding the BD study, a mean (SDS) of -1.62 (1.32) ranged between -3.90 and 0.70 was found. The result after adjusting for height/age showed a significant difference with a mean of 0.39 (1.18) [-2.0 to 2.40], and no differences according karyotype and adiposity.
Conclusion: Prepubertal TS girls had normal bone density when adjusted for height/age, without influence of karyotype and BMI. Lower BD values are associated with the short stature bias, and when the results are adjusting for height/age, the values are within normal limits.
19 Sep 2019 - 21 Sep 2019